Thermal processes such as baking, roasting, and frying involve simultaneous heat and mass transfer phenomena. Heat is transferred from the surrounding air or oil into the interior of the food, while moisture and some volatile compounds escape from the food towards the exterior or surrounding air due to evaporation. This results in high-temperature and low-moisture conditions during these processes, which lead to the formation of Maillard reaction products. A diverse range of new molecules, some of which have been associated with beneficial health effects, are generated. Conversely, undesirable compounds, such as acrylamide, may also be formed, exhibiting carcinogenic and, in certain instances, mutagenic properties. The precursors present in foods, including amino acids, sugars, vitamins, and fatty acids, are involved in these chemical reactions, leading to the formation of thermal process contaminants. This presentation is about the formation, mechanism and further reactions of Maillard reaction products, primarily acrylamide, which are formed in foods during heat treatment and have potentially toxic effects.